Applicant claims priority under 35 U.S.C. xc2xa7119 of Austrian Application No. GM672/98 filed on Oct. 14, 1998. Applicant also claims priority under 35 U.S.C. xc2xa7120 of PCT/AT99/00228 filed on Sept. 21, 1999. The international application under PCT article 21(2) was not published in English.
The invention relates to an axial securing device for an end of a pivot axle of a hand stamp comprising a self-inking device, wherein the pivot axle extends through a character unit accommodated in a stamp housing as well as through guiding slots in the side walls of the stamp housing, the ends of the pivot axle being held in openings in legs of an actuating bow, which actuating bow is movable relative to the stamp housing, the axial securing device comprising an annular member capable of being snapped onto the end of the pivot axle, which annular member comprises at least one radially inward snap projection for snapping engagement in a peripheral groove adjacent the outer end of the pivot axis.
Furthermore, the invention relates to a hand stamp comprising at least one such axial securing device.
From U.S. Pat. No. 5,058,501 A, a hand stamp comprising a self-inking device is known, in which a character unit accommodated in a stamp housing is pivoted about a pivot or inverting axle during actuation of the stamp so that it is moved from an inking position, in which the priting characters face upwardly and there contact an inking pad, into an active position in which the printing characters previously inked on the inking pad.
In this known hand stamp, the pivot axle for the character unit is secured on both axle ends by outer Seeger circlip ring-type annular members; these annular members engage in a peripheral groove of the axle by means of radially inwardly projecting latch projections. Within these annular members, bearing rings having a stepped configuration in axial section are provided in both end regions of the pivot axle, said bearing rings being inserted with their smaller diameter regions in the bearing opening of the respective actuating leg, and being engaged in the longitudinal slot-provided in the side walls of the stamp housing for upward and downward movement of the pivot axle. The inner, stepped bearing ring forms a spacer element with its annular flange of larger diameter, so as to maintain the stamp housing and the neighbouring actuating bow leg at a predetermined distance from each other. This axial securing means with the bearing rings as well as with the safety ring member ensures the possibility of a rotational movement of the pivot axle relative to the stamp housing and to the actuating bow, wherein, furthermore, by the rotatability of the bearing rings, little wear of the latter on the stamp housing as well as on the actuating bow is ensured even if these parts are made of metal, as usual, whereas the bearing rings are made of plastics.
A disadvantage with this known solution is, how-ever, that several rings, or annular members, respectively, have to be attached on each axle end, i.e. at different relative positions as regards the remaining components of the hand stamp; this makes mounting of the axle or the assembly of the stamp housing with the actuating bow, respectively, extremely cumbersome and complex. Yet, above all, the attachment of annular members is also disadvantageous with a view to an automatic assembly of the hand stamp, as is desired in principle. Moreover, for merely securing the axle, three individual parts have to be produced and kept on store, which also complicated matters.
From AT 379,552 B, furthermore, a self-inking Stamp comprising upper self-inking means is known, in which retention disks are snapped from outside onto the ends of the pivot axle; in this manner only an axial securing of the pivot axle is realized which the previously discussed disadvantages, mainly with regard to the mounting of the axle, resulting therefrom.
It is now an object of the invention to provide an axial securing device of the initially defined type which facilitates the mounting of the pivot axle or of the assembly of the components of the hand stamp, respectively, and simultaneously ensures a bearing or guiding of the axle in the bearing housing and in the actuating bow, wherein the rotatability and endurance shall also be ensured if such components are made of metal.
The inventive axial securing device of the initially defined type is characterized in that the annular member is formed to be integral with a bearing sleeve which, with the axial securing device mounted, extends through the actuating bow leg as well as through the longitudinal slot in the side wall of the stamp housing.
The invention thus provides an axial securing device with integrated guide means, or integrated bearing part, respectively, in the form of a bearing sleeve which offers the advantage that on the (preferably, on each) axle end of the pivot axle only one structural element must be mounted; it is a further advantage that the axial securing device element can be snapped onto the axle end from the outside when the stamp housing and the actuating bow have already been brought into their respective relative positions so that also the previously mentioned snap-on procedure can be effected in a simple manner, in particular automatically.
For mounting and dismounting of the thus generally nipple-type axial securing element it is particularly advantageous if the annular member is formed by several annular segments projecting from the front end of the bearing sleeve and separated from each other by slots. By the presence of several annular segments separated from each other by slots, a resilient deflection of these annular segments relative to the bearing sleeve from which they project axially as well as radially is comparatively easily possible when they are snapped onto the axle ends just like when they are removed therefrom, as compared to a closed annular form in which snapping on or removal has to be performed by an elastic material deformation of the inner snap projection(s). With a view to a simple manufacture as well as to a favorable configuration for snapping on and removal, it has proven to be a particularly advantageous compromise if four annular segments are provided, each corresponding approximately to a quarter circular arc seen in front end view, separated from each other by slots extending perpendicular relative to each other.
It is also suitable if the annular member and the bearing sleeve together are injection-molded of plastics, such as, e.g., POM (polyoxymethylene). By such a production as an injection-molded part, an especially cost-saving production is ensured. As the materials, in principle also other plastics materials suitable for injection molding may be used, in particular thermo-plastic materials, such as PMA (polymethacrylate), PMMA (polymethyl-methacrylate) or ABS (acrylonitrile-butadiene-styrene).
A further object of the invention is a hand stamp comprising at least one axial securing device according to the invention. There, too, the invention preferably provides for a hand stamp wherein on a guiding part guiding the legs of the actuating bow in a manner known per se and attached on the stamp housing, at least one lug plate is molded which extends as a spacer element into the gap between the stamp housing and the respective actuating bow leg. With this design, a substitute for the annular flanges of the bearing rings serving as spacers of the hand stamp known from U.S. Pat. No. 5,058,501 A is provided by the at least one lug plate on the guiding part which acts as a spacer, so that in the region of this (these) lug plate(s), i.e. in the region of the lower rim of the guiding part, the legs of the actuating bow are held at a pre-determined distance from the outer side of the side walls of the stamp housing. Thus, said lug plate(s) assume(s) the spacer and guiding function for the respective leg of the actuating bow during downward movement of the latter relative to the stamp housing, which functions, at the known stamp, are carried out by the flanges of the separate bearing rings located on the pivot axle, which bearing rings are dispensed with by the configuration of the present axial securing device comprising the bearing sleeve of uniform outer diameter.